Diablo 3 decals = SC2 Achievement

The images you see to the right were found deep within the bowels of the official Starcraft 2 site, and are presumed to be unlockable decals awarded as achievements on Battle.net. The ones you see here are the three versions of Diablo’s head/skull; click the image for the full list, all the rest of which seem to be SC2 or WoW-themed. How these will be unlocked or activated is unknown; presumably by winning matches over Battle.net.